The obverse of the early Roman denarii bore, next to the mark of value X for 10 asses, the head of the goddess Roma with a winged helmet. The reverse depicted the Dioscuri Castor and Pollux and the inscription ROMA.
The twins Castor and Pollux were said to have helped the Romans in 499 BC in the Battle on Lake Regillus against the Latin League. Since then they were worshipped in Rome and considered to be supporters of the Romans.